KMM Application Cannot Run In Simulator - ios

Question

I am new to KMM and I am trying to integrate KMM project as a pod to my sample Xcode Project. I can link the KMM Pod to my Xcode project. However if I try to call one of the function, below error yielded. If I do not call any of the KMM function, it can run the app in my simulator.
ViewController
import UIKit
import Multiplatform
class ViewController: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
let a = Greeting()
a.greeting()
}
}
ld: warning: ignoring file /Users/avjiang/Developments/Multiplatform/SharedCode/build/cocoapods/framework/Multiplatform.framework/Multiplatform, building for iOS Simulator-arm64 but attempting to link with file built for iOS Simulator-x86_64
Undefined symbols for architecture arm64:
"_OBJC_CLASS_$_MultiplatformGreeting", referenced from:
objc-class-ref in ViewController.o
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
The KMM application is just a simple app. There is a Greeting class inside SharedCode -> commonMain -> kotlin -> Greeting
Below is my configuration for build.gradle.kts
import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinNativeTarget
plugins {
kotlin("multiplatform")
kotlin("native.cocoapods")
id("com.android.library")
}
version = "1.0"
kotlin {
android()
cocoapods {
// Configure fields required by CocoaPods.
summary = "Some description for a Kotlin/Native module"
homepage = "Link to a Kotlin/Native module homepage"
frameworkName = "Multiplatform"
ios.deploymentTarget = "13.5"
podfile = project.file("/Users/avjiang/Developments/TestKotlinMultiplatformPod/Podfile")
}
val iosTarget: (String, KotlinNativeTarget.() -> Unit) -> KotlinNativeTarget =
if (System.getenv("SDK_NAME")?.startsWith("iphoneos") == true)
::iosArm64
else
::iosX64
iosTarget("ios") { }
sourceSets {
val commonMain by getting
val commonTest by getting {
dependencies {
implementation(kotlin("test-common"))
implementation(kotlin("test-annotations-common"))
}
}
val androidMain by getting
val androidTest by getting {
dependencies {
implementation(kotlin("test-junit"))
implementation("junit:junit:4.13.2")
}
}
val iosMain by getting
val iosTest by getting
}
}
android {
compileSdkVersion(30)
sourceSets["main"].manifest.srcFile("src/androidMain/AndroidManifest.xml")
defaultConfig {
minSdkVersion(19)
targetSdkVersion(30)
}
}
And this is my project build.gradle.kts
buildscript {
repositories {
gradlePluginPortal()
google()
mavenCentral()
}
dependencies {
classpath("org.jetbrains.kotlin:kotlin-gradle-plugin:1.5.20")
classpath("com.android.tools.build:gradle:4.2.2")
}
}
allprojects {
repositories {
google()
mavenCentral()
}
}
tasks.register("clean", Delete::class) {
delete(rootProject.buildDir)
}
Basically I am just following the tutorial from https://kotlinlang.org/docs/mobile/create-first-app.html. Nothing complex yet. Is there anything I missed out?
My machine configuration:
Mac mini M1
Xcode 13 beta 2
MacOS 11.4
Thank you

Answer 1

The error:
ld: warning: ignoring file /Users/avjiang/Developments/Multiplatform/SharedCode/build/cocoapods/framework/Multiplatform.framework/Multiplatform, building for iOS Simulator-arm64 but attempting to link with file built for iOS Simulator-x86_64
You're trying to build for the M1 chip simulator, Simulator-arm64, but KMM does not support that yet. Your KMM build is for Intel, Simulator-x86_64.
For M1 Macs, you'll need to run this on your actual iPhone device or run Xcode under Rosetta (thanks to Philip in the comments).

Answer 2

You need to import shared because KMM uses shared module.